Digital processing and comparison device

Abstract

A digital processing and comparison indicating apparatus is responsive to an input signal having a value proportional to the quantity to be indicated for displaying a quantity of electrical information in an analog form of decimal notation. A microprocessor compares the value of the input signal with a first plurality of reference values and generates decade enable signals for each one of the first reference values which are less than or equal to the input signal value. The microprocessor also compares the input signal value with a second plurality of reference values and generates units enable signals for each one of the second reference values which are less than or equal to the difference between the input signal value and the value of the largest one of the first reference values for which first enable signals have been generated. The decade and units enable signals drive a display which typically includes a plurality of light emitting diodes for indicating the quantity of the electrical information. This display can have the decades indicating LEDs positioned in a semi-circle or circle and the units indicating LEDs positioned in a straight line for improved readability.

What is claimed is: 
     
       1. A method of indicating a quantity of electrical information represented by an input signal having a value proportional to the quantity to be indicated comprising the steps of: a. generating a plurality of reference signals each having a different value;   b. individually comparing the value of the input signal with each of said reference signals in a predetermined order until the value of the input signal falls between the values of two consecutive ones of said reference signals;   c. storing a plurality of first indicating signals corresponding to each of said reference signals having values equal to and less than the value of the lesser one of said two consecutive reference signals in step (b);   d. subtracting the value of said lesser one of said two consecutive reference signals in step (b) from the value of the input signal and storing at least one second indicating signal representing the value of the difference; and   e. generating an indication of the quantity of electrical information represented by the input signal in response to said first and second stored indicating signals.